This article presents the results of an assessment of the potential for the use of CNG in Poland as a fuel for passenger cars powered by an internal combustion engine fuelled by petrol or diesel. The basis for assessing the potential was an analysis of the economic efficiency of converting a passenger car fuelled by petrol or diesel to a dual-fuel vehicle by installing a CNG system. On the basis of available literature data, the vehicle structure was characterised using the following criteria: vehicle age, engine capacity, car-segment, type of fuel used and kerb weight. The average fuel consumption (petrol or diesel) of the vehicle before conversion was determined on the basis of specially developed statistical models. The conversion and operating costs of a vehicle fuelled with conventional fuel and with CNG (after vehicle conversion) were estimated on the basis of a stochastic simulation model using probability density distributions of vehicle parameters and the Monte Carlo method. The vehicle parameters were estimated so that the obtained set of vehicles reflected the actual structure of passenger cars in Poland. The estimated costs of vehicle conversion (purchase and installation of a CNG system) and its subsequent operating costs made it possible to assess the economic efficiency of the car conversion process. The potential use of CNG as a fuel for combustion cars was estimated by comparing the operating costs of a vehicle before conversion and the operating costs of a vehicle after conversion, taking into account the costs of conversion. Analogous calculations were carried out for the conversion of a vehicle to run on LPG, i.e. the most important competitor to CNG.

An algorithm of determination of mechanical stresses and deformations of the magnetic circuit shape, caused by forces of magnetic origin, is presented in this paper. The mechanical stresses cause changes of magnetizing characteristics of the magnetic circuit. The mutual coupling of magnetic and mechanical fields was taken into account in the algorithm worked out. A computational experiment showed that it was possible to include the interaction of both fields into one numerical model. The elaborated algorithm, taking into account the impact of mechanical stresses on magnetic parameters of construction materials, can be used in both the 2D and the 3D type field-model.

The orientations of recrystallization nuclei and their adjacent as-deformed regions have been characterised in deformed single crystals of different metals (Ag, Cu, Cu-2%wt.Al and Cu-8%wt.Al) in which twinning and/or shear banding occur. {112}<111> oriented crystals of these metals have been compressed to different strains, then lightly annealed, and the crystallographic aspects of the recrystallization process along shear bands examined by local orientation measurement in TEM and SEM. The results clearly show the existence of a well-defined crystallographic relation between the local deformation substructure and the first recrystallized areas of uniform orientation. The first-formed nuclei always exhibit near 25–400(<111>–<112>) type misorientations, in the direction of highest growth, with respect to one of the two main groups of the deformation texture components. The rotation axes can be correlated with the slip plane normal of highest activity. As recrystallization proceeds, recrystallization twinning develops strongly and facilitates rapid growth; the first and higher generations of twins then tend to obscure the initial primary crystallographic relation between the shear bands and recrystallization nuclei .

Experimental design and computational model for predicting debonding initiation and propagation are of interest of scientists and engineers. The design and model are expected to explain the phenomenon for a wide range of loading rates. In this work, a method to measure and quantify debonding strength at various loading rates is proposed. The method is experimentally verified using data obtained from a static test and a pulse-type dynamic test. The proposed method involves the cohesive zone model, which can uniquely be characterized with a few parameters. Since those parameters are difficult to be measured directly, indirect inference is deployed where the parameters are inferred by minimizing discrepancy of mechanical response of a numerical model and that of the experiments. The main finding suggests that the design is easy to be used for the debonding characterization and the numerical model can accurately predict the debonding for the both loading cases. The cohesive strength of the stress-wave case is significantly higher than that of the static case; meanwhile, the cohesive energy is twice larger.